What Causes Vertigo With Dizziness?

Hi I am 43 years old female, always been healthy . For two days I am expiriencing a vertigo/dizzines when at night I change sleeping positions from by back to the left side or to the right side. Recently I an exercise bar/pull-up fell on my head, i didn't feel too much pain, since the bar is preety well padded. I do have some ear ace time from time, not often left from my cold symptoms. I do have some scoliosis in my spine, but overoll I am very healthy person. Why do I have dizzines now? never had it before...